/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.commons.net.ftp.parser;

import java.text.ParseException;

import org.apache.commons.net.ftp.FTPClientConfig;
import org.apache.commons.net.ftp.FTPFile;

/**
 * Implementation of FTPFileEntryParser and FTPFileListParser for Netware Systems. Note that some of the proprietary
 * extensions for Novell-specific operations are not supported. See 
 * <a href="http://www.novell.com/documentation/nw65/index.html?page=/documentation/nw65/ftp_enu/data/fbhbgcfa.html">http://www.novell.com/documentation/nw65/index.html?page=/documentation/nw65/ftp_enu/data/fbhbgcfa.html</a>
 * for more details.
 *
 * @author <a href="rwinston@apache.org">Rory Winston</a>
 * @see org.apache.commons.net.ftp.FTPFileEntryParser FTPFileEntryParser (for usage instructions)
 * @version $Id$
 */
public class NetwareFTPEntryParser extends ConfigurableFTPFileEntryParserImpl {

	/**
	 * Default date format is e.g. Feb 22 2006
	 */
	private static final String DEFAULT_DATE_FORMAT = "MMM dd yyyy";

	/**
	 * Default recent date format is e.g. Feb 22 17:32
	 */
	private static final String DEFAULT_RECENT_DATE_FORMAT = "MMM dd HH:mm";

	/**
	 * this is the regular expression used by this parser.
	 * Example: d [-W---F--] SCION_VOL2                        512 Apr 13 23:12 VOL2
	 */
	private static final String REGEX = "(d|-){1}\\s+"	// Directory/file flag 
			+ "\\[(.*)\\]\\s+"			// Attributes
			+ "(\\S+)\\s+" + "(\\d+)\\s+"		// Owner and size
			+ "(\\S+\\s+\\S+\\s+((\\d+:\\d+)|(\\d{4})))" // Long/short date format
			+ "\\s+(.*)";				// Filename (incl. spaces)

	/**
	 * The default constructor for a NetwareFTPEntryParser object.
	 *
	 * @exception IllegalArgumentException
	 * Thrown if the regular expression is unparseable.  Should not be seen
	 * under normal conditions.  It it is seen, this is a sign that
	 * <code>REGEX</code> is  not a valid regular expression.
	 */
	public NetwareFTPEntryParser() {
		this(null);
	}

	/**
	 * This constructor allows the creation of an NetwareFTPEntryParser object 
	 * with something other than the default configuration.
	 *
	 * @param config The {@link FTPClientConfig configuration} object used to 
	 * configure this parser.
	 * @exception IllegalArgumentException
	 * Thrown if the regular expression is unparseable.  Should not be seen
	 * under normal conditions.  It it is seen, this is a sign that
	 * <code>REGEX</code> is  not a valid regular expression.
	 * @since 1.4
	 */
	public NetwareFTPEntryParser(FTPClientConfig config) {
		super(REGEX);
		configure(config);
	}

	/**
	 * Parses a line of an NetwareFTP server file listing and converts it into a
	 * usable format in the form of an <code> FTPFile </code> instance.  If the
	 * file listing line doesn't describe a file, <code> null </code> is
	 * returned, otherwise a <code> FTPFile </code> instance representing the
	 * files in the directory is returned.
	 * <p>
	 * <p>
	 * Netware file permissions are in the following format:  RWCEAFMS, and are explained as follows:
	 * <ul>
	 * <li><b>S</b> - Supervisor; All rights.
	 * <li><b>R</b> - Read; Right to open and read or execute.
	 * <li><b>W</b> - Write; Right to open and modify.
	 * <li><b>C</b> - Create; Right to create; when assigned to a file, allows a deleted file to be recovered.
	 * <li><b>E</b> - Erase; Right to delete.
	 * <li><b>M</b> - Modify; Right to rename a file and to change attributes.
	 * <li><b>F</b> - File Scan; Right to see directory or file listings.
	 * <li><b>A</b> - Access Control; Right to modify trustee assignments and the Inherited Rights Mask.
	 * </ul>
	 * 
	 * See <a href="http://www.novell.com/documentation/nfap10/index.html?page=/documentation/nfap10/nfaubook/data/abxraws.html">here</a> 
	 * for more details
	 * 
	 * @param entry A line of text from the file listing
	 * @return An FTPFile instance corresponding to the supplied entry
	 */
	public FTPFile parseFTPEntry(String entry) {

		FTPFile f = new FTPFile();
		if (matches(entry)) {
			String dirString = group(1);
			String attrib = group(2);
			String user = group(3);
			String size = group(4);
			String datestr = group(5);
			String name = group(9);

			try {
				f.setTimestamp(super.parseTimestamp(datestr));
			} catch (ParseException e) {
				return null; // this is a parsing failure too.
			}

			//is it a DIR or a file
			if (dirString.trim().equals("d")) {
				f.setType(FTPFile.DIRECTORY_TYPE);
			} else // Should be "-"
			{
				f.setType(FTPFile.FILE_TYPE);
			}

			f.setUser(user);

			//set the name
			f.setName(name.trim());

			//set the size
			f.setSize(Long.parseLong(size.trim()));

			// Now set the permissions (or at least a subset thereof - full permissions would probably require 
			// subclassing FTPFile and adding extra metainformation there)
			if (attrib.indexOf("R") != -1) {
				f.setPermission(FTPFile.USER_ACCESS, FTPFile.READ_PERMISSION,
						true);
			}
			if (attrib.indexOf("W") != -1) {
				f.setPermission(FTPFile.USER_ACCESS, FTPFile.WRITE_PERMISSION,
						true);
			}

			return (f);
		}
		return null;

	}

	/**
	 * Defines a default configuration to be used when this class is
	 * instantiated without a {@link  FTPClientConfig  FTPClientConfig}
	 * parameter being specified.
	 * @return the default configuration for this parser.
	 */
	protected FTPClientConfig getDefaultConfiguration() {
		return new FTPClientConfig(FTPClientConfig.SYST_NETWARE,
				DEFAULT_DATE_FORMAT, DEFAULT_RECENT_DATE_FORMAT, null, null,
				null);
	}

}
